Bringing beavers back to Scotland

Hoopla surrounds experiment to reintroduce wild beavers, extinct in the British Isles for 400 years, into Scotland

Bringing beavers back to Scotland

Steve Gardner / Scottish Beaver Trial

An experiment designed to assess the effects of releasing beavers into the wild has both fascinated and inflamed the public.

Bringing beavers back to Scotland

Steve Gardner / Scottish Beaver Trial

Roisin Campbell-Parker, right, of the Royal Zoological Society of Scotland, and colleague Christian Robstad attach a monitoring tag to the back of a beaver. The data-gathering portion of the trial has ended, and the reports are to be presented to parliament in May.

The world is a big place, but it is probably safe to assume there is only one scientific trial on the planet with 1,750 Facebook friends and an official mascot named Bruce.

Such is the hoopla surrounding the Scottish Beaver Trial, an experiment in Argyll, Scotland, designed to assess the effects of releasing families of wild beavers into a patch of forest — and perhaps, eventually, across the rest of the country. Beavers have been extinct in the British Isles for more than 400 years. If the five-year trial is deemed a success, the animals will be the U.K.’s first-ever formal reintroduction of a lost mammal.

The project has fascinated and inflamed the public. This May, the Scottish government will be presented with evidence gathered from Argyll that shows how the beavers have impacted their environment, from river ecology to dragonfly populations and rare lichens. Then it must decide whether to proceed with the nationwide experiment in “rewilding,” a British buzzword these days.

But beavers may come back with or without parliamentarians’ blessings. Two unsanctioned populations have already cropped up on distant rivers, one on the eastern coast of Scotland and one in Devon, England. How they got there, no one can say.

“Whether it’s an accidental escape or whether someone’s deliberately put them in the river, we don’t know,” said Peter Burgess, conservation manager for the Devon Wildlife Trust, the charity that has taken over management of the southern population.

Passions run so high over beavers that a rogue reintroduction of the rodent is not particularly far-fetched — a fact that might amuse a Canadian with a pocket full of beaver-stamped nickels. But those passions aren’t universally positive. Farmers and anglers are concerned the beavers will interfere with livelihoods. Government officials threatened to destroy the two unofficial beaver populations for fear they would introduce parasites. Others are agog at the spectre of wolf and lynx reintroductions, two other species long-lost from the land.

“The Scottish Beaver Trial is not about beavers. It’s about people,” said Simon Jones, director of conservation for the Scottish Wildlife Trust.

In the Pleistocene — the age of enormous megafauna like mastodon, megaceros and the woolly mammoth — multiple species of beaver roamed the Earth, including Trogontherium and Castoroides ohioensis, giant rodents that weighed up to 100 kilograms. Today, just two species are left: Castor fiber, the Eurasian beaver, and Castor canadensis, the North American beaver.

Castor canadensis has a bigger tail and better engineering chops, constructing large dams out of any kind of tree it can get its teeth on. Castor fiber has bigger litters and relies mostly on willow to make more modest homes, known as lodges, on riverbanks.

To a haberdasher, however, a beaver is a beaver. As the popularity of felt hats rose in 18th{+-} and 19th-century England, beaver numbers dropped fast, prompting expeditions to the New World, where pelts were plentiful. Beavers disappeared from England and Wales between the 12th and 13th centuries, from Scotland by the 16th century, and as few as 1,200 were left on the European continent by the beginning of the 20th century. North American beaver populations eventually saw declines, too.

Throughout the last century, those trends began to reverse. Germany, Finland, Sweden, Russia, Poland and a handful of other countries actively reintroduced the animals to their wetlands, and European beaver numbers have ballooned 900-fold over the last 100 years, according to data presented by researcher Dietland Muller-Schwarze in The Beaver: Its Life and Impact.

But the paddle across the English Channel is too much to ask of a semi-aquatic beaver, whose swimming speed maxes out at 7 km/h. Seeing numbers rising on the continent, Scottish conservationists in the mid- to late-1990s began to think about actively reintroducing the species in their own wetlands.

“For us, the issue is not just about, ‘Isn’t it nice to bring back an interesting fluffy mammal that people quite like to watch in the wild.’ It’s what beavers do,” said Jones.

Beavers are considered keystone species, organisms whose presence or absence dramatically alters an ecosystem. Their dams are, well, dams — they raise water levels and change the flow of rivers, reducing erosion and altering sedimentation. The resulting ponds and marshes create habitats for all kinds of other species, both plant and animal, boosting biodiversity. Beavers are considered environmental engineers.

Yet Scotland and England no longer boast much “natural” environment. “Our landscape has changed so much and become so modified since 400 years ago, there was questioning of whether this animal should be brought back, especially since it comes with a price tag,” said Roisin Campbell-Palmer, conservation projects manager for the Royal Zoological Society of Scotland. Farmers worried dammed drainage ditches would flood fields. Anglers, citing data from eastern Canada, were strident that dams would interfere with salmon migration. One Scottish landowner later called beavers “destructive nocturnal rats.”

Given the concerns, a trial was deemed the best way to proceed. The requisite permissions were slow to arrive — parliament vetoed the proposal in 2005 under pressure from interest groups — but Scotland’s environment minister finally granted a license for the trial in May 2008. Four months later, a team of wildlife experts found themselves adrift in Norwegian waters in the middle of the night, holding nets and looking for Eurasian beavers.

After a period of quarantine, the official trial began in May of 2009, when three beaver families were released into a 44-square-kilometre patch of Argyll’s Knapdale Forest, a two-hour drive west of Glasgow.

Even before the first beaver families were loosed in the forest, beaver-related rumblings were emanating from the River Tay on Scotland’s eastern coast. As early as 2006, Scottish wildlife agencies had seen evidence of a beaver population in this region 200 kilometres east of Knapdale.

“There are some private collections in the area, so it’s very likely they escaped … but also there was a bit of an underground conservation movement that was really frustrated with the slowness of process,” said Campbell-Palmer. “Whether they were accidentally or purposely released in that area, now we’ve got the situation where we’ve got the official trial on one side of Scotland and this quite large, expanding population of beavers on the other part.”

Then, in 2013, residents living near the River Otter in Devon, 900 kilometres south of Knapdale, began noticing sharpened tree stumps. Tom Buckley, a retired environmental scientist, remembers wondering “if we’ve got some of the local lads down there messing about.” He set up a camera to catch the kids.

Instead, he found himself with the first documented evidence of beavers in England since the Middle Ages.

“It hit the news and then it just mushroomed from there,” said Buckley. The government threatened to remove both populations, but eventually granted approval to study the two groups, provided wildlife experts could prove they were Eurasian beavers and were free of parasites.

In Argyll, beaver fever is downright virulent: Jones calculates that at least 31,000 people have visited Knapdale or attended talks, walks and other beaver events over the course of the trial.

But anglers, farmers and landowners are still not enthusiastic. In 2012, the National Farmers Union of Scotland called for a moratorium on reintroduced species. In return, the writer and environmentalist George Monbiot accused Britain and its landowners of being “zoophobic.” Monbiot’s book Feral, in which he openly advocates for the reintroduction of wolves, lynxes and bison, inserted the term “rewilding” into the national conversation.

Last year, after the conclusion of the data-gathering portion of the trial, Bruce the beaver mascot and his conservationist minders visited Scottish parliament, where Bruce mugged for the cameras alongside current and former environment ministers.

Though more than a dozen beaver babies were born during the trial, the reports found very little significant impact from the animals: the trial was small enough that its main conclusion was that there were no overwhelmingly negative effects.

Once the reports are presented to parliament in May, a decision on the fate of Scotland’s beavers is expected within the year. Left alone, the Knapdale population is too small to survive unassisted.

To Jones’ mind, the trial has already shown that beavers can thrive in Scotland.

“It would be a common widespread animal here in time, as it is in Canada, if we decide to allow that to happen,” he said.

“Beavers can live in Scotland again absolutely fine. The big question is really about whether we want them.”